The present application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. xc2xa7119 from an application entitled Hinge Apparatus For Portable Radiophone Having Multi-Angled Hinge filed in the Korean Industrial Property Office on May 31, 2001 and assigned Ser. No. 30472/2001 by the Office.
1. Field of the Invention
The present invention relates to a portable communications terminal (i.e., mobile telephone) in a mobile communications system and, in particular, to a hinge apparatus capable of optionally adjusting the extent of opening/closing a folder from a main body of the portable communications terminal.
2. Description of the Related Art
In general, portable communications terminals include a variety of portable radiophones, such as cellular phones, hand-held phones, cordless telephones (CT-2), personal communications service (PCS) phones. Such a portable radiophone carries out radio communication with its adjacent base station in order to provide its user (calling party) with a radio communications service with any called party.
Recently, the radio communications services provided with the portable radiophones have been extending toward a visual (picture) communications service as well as a voice communications service in accordance with rapid development of the telecommunications technology. In the cases where such visual communication is being served, a user needs to face directly toward an eye of camera lens in his radiophone to effect the visual communications with any called party on the phone. When a user watching any visual content, such as a book or a movie on his radiophone, he may often need to adjust an LCD display window, usually located on a folder of his portable radiophone, in a best possible position or viewing angle over its main body. Hence, there is a need for a portable communications terminal capable of optionally adjusting an opening/closure angle of a folder.
Commonly, portable communications terminals are classified into bar type, flip type and folder type according to their appearance. With the development of smaller and lighter terminals, they also include a neck wearable type of phones and a wrist or watch type of phones according to their convenience of wearing. Some of the portable communications terminals are often and optionally provided with a set of lens assemblies to enable the face-to-face visual communication with the called party.
Of the aforementioned three types of portable communications terminals, the flip type or folder type of terminals consists of at least two housings, i.e., a main body and a sub body, of which construction essentially entails a hinge apparatus for pivotally connecting the two housings. This hinge apparatus conventionally serves to couple those two housings, i.e., a main body and a sub body, on a pivot axis and to control the movement of the sub body onto the main with a predetermined limit of opening/closure angle upon using it.
One of such a type of prior art hinge apparatus is disclosed in a Korean patent publication No. 1999-87915, which is commonly assigned to the same assignee of the present application. This hinge apparatus however, is related to a hinge apparatus for providing only a closing drive power into the main body when a folder is positioned closed on the main body, while providing only an opening drive power when the folder is opened by about 45xc2x0, and providing only a stopping drive power when the folder is opened by about 150xc2x0 or more with respect to the main body. Therefore, it is not possible for a user of the portable phone to stop the folder in an angular position of about 100xc2x0 with respect to the main body upon opening it.
As a result, such a prior art hinge apparatus creates a problem in that it cannot control the folder to halt in a desired angular position with respect to the main body when using the terminal in the visual communications service mode, although it does not create any significant problems when using the terminal in the voice communications service mode. Accordingly, a user of the prior art hinge apparatus is inconvenienced when using the terminal in the visual communications service mode, since he often needs to pose face-to-face with the camera lens of the portable terminal after the folder is fully opened.
Therefore, it is noted that the above prior art hinge apparatus is considerably disadvantageous for comfortably utilizing the mobile visual/picture communications services such as video phone, television watching, electronic books, etc., when placing the portable terminal on a table or desk to use the terminal without being hand held, because the folder is always automatically set to be fully open by a single predetermined angle with respect to the main body. Thus, any free adjustment of the opening angle of the folder is not provided for watching an LCD display window on the folder in its best-suited angle. As a result, a more flexible adjustment of the opening angle of the folder in a foldable terminal is becoming important to meet the users"" increasing requirements for the multi-media environment that is very rapidly being introduced into the mobile visual communication service.
It is, therefore, an object of the present invention to provide a hinge apparatus capable of making a folder of a portable communications terminal stop in any desired angular position in accordance with an eye level of its user, preferably, but not exclusively, when using the terminal in the mobile visual (picture) communications mode such as in video teleconference, video phone, watching on TV/cinema, or e-books, etc., thereby providing the user with more convenience.
It is another object of the present invention to provide a hinge apparatus capable of optionally controlling an opening/closure angle of a folder of a foldable type of portable communications terminal in a desired angular position between 50xc2x0 and 150xc2x0 in accordance with an eye level of its user.
Accordingly, to achieve the above and other objects of the present invention, a hinge apparatus for a portable communications terminal includes a main body having no opposite sides at its opposed end a pair of hinge arms positioned apart from each other in an axis; a folder having at one end a center hinge arm disposed between the pair of hinge arms on the same axis, one end of the center hinge arm being provided with a cavity; a hinge housing fixed to the cavity of the center hinge arm on the same axis, one of two opposed ends of the hinge housing being provided with a through hole; a hinge shaft having an extension part further extending to the axial direction through the through hole, and a sliding peak disposed within the hinge housing in the opposed position to the extension part, the extension part being fixedly inserted to a hole of one of the pair of hinge arms; a hinge cam movably disposed within the hinge housing on the axis, having a slot section engaging the sliding peak of the hinge shaft, the hinge cam being rotatable together with the hinge housing; and a hinge spring disposed between the other end of the hinge housing and one end of the hinge cam, having a spring tension in the axial direction.
In one end of the hinge cam, on its guide axis, is formed a pair of projections disposed opposed to each other, and a recessed slot formed in between the pair of projections. In both ends of the projections are respectively formed side sliding surfaces of a first predetermined slanting angle and an upper sloped surface of a second predetermined slanting angle. A guide protrusion is formed in one of the projections so that upon rotation of the folder with respect to the main body, the sliding peak of the hinge shaft come into surface contact with the sloped surface of the hinge cam, causing the folder to stop at the intended angular position.
Preferably, the slot section between the pair of projections may be of the form of V-shape valley.
Preferably, the side sliding surfaces of the pair of projections are slanted to the upper sloped surface of the pair of projections and the upper sloped surfaces of the pair of projections are formed to slant to the opposite direction to each other.
Preferably, the first predetermined slanting angle of the side sliding surfaces of the pair of projections may be of a range from 10 to 20 degrees and the second predetermined slanting angle of the upper sloped surfaces may be of a range from 0 to 10 degrees. Most preferably, a blocking means for preventing further rotation is provided to one end of the projection